RCgothic

Members
  • Content Count

    925
  • Joined

  • Last visited

Community Reputation

1,136 Excellent

1 Follower

About RCgothic

  • Rank
    Chartered Engineer

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. Did some maths on 8 EOR mission modes: 1. Europa Clipper on Falcon Heavy (expendable). C3 = 73.5. The baseline for comparison. Doesn't quite match SLS Block 1, and isn't good enough for a direct trajectory to Europa. 2. Europa Clipper plus STAR48 on Falcon Heavy (expendable). C3 = 78.6. The addition of a third stage is a big improvement, but it's still not good enough for a direct trajectory to Europa. Beats SLS Block 1, which isn't good enough either. Likely actual mission mode. 3. Europa Clipper on F9 RTLS, docked to FHUS (2xASDS) in LEO. C3 - 72.9. Worse than the baseline. The loss of 6t of FHUS propellant by reserving booster margin for side core recover isn't compensated by 6t additional F9 payload. 4. Europa Clipper on F9 RTLS, docked to FHUS (expendable) in LEO. C3 - 82.2. Whereas this is just about the minimum required for a direct trajectory. Not quite SLS Block1B, but it gets the mission done for a fraction of the price even expending 3 of 4 cores. 5. Europa Clipper plus STAR48 on F9 RTLS, docked to FHUS (2xASDS) in LEO. C3 - 81.2. Not as good as 4, and probably just short of a direct trajectory. You could maybe get away with just 80 at the optimum launch window. The loss of 6t of FHUS propellant by reserving booster margin for side core recover isn't compensated by sending EC up on F9 or by the small kick stage. 6. Europa Clipper plus STAR48 on F9 RTLS, docked to FHUS (expendable) in LEO. C3 = 90.4. Easily direct to Europa. Beats SLS Block 1B as well. Does lose 3 of 4 cores, but this is negligible compared to the comparative cost of SLS. 7. Europa Clipper plus SUPERSTAR on F9 ASDS, docked to FHUS (2xASDS) in LEO. C3 = 94. Competitive with SLS Block 2 for performance and recovers 3 of 4 cores (JRTI2, OCISLY and ASoG required). 8. Europa Clipper plus SUPERSTAR on F9 ASDS, docked to FHUS (expendable) in LEO. C3 = 102.5. Roflstomps SLS Block 2 for a fraction of the price. Can send ludicrously large probes to anywhere.
  2. I'm really not a fan of the orange insulation. SpaceX is in a prime position for an EOR mission. Falcon 9 could probably stick Europa Clipper AND a Star48B PAM in LEO without even breaking a sweat. RTLS from SLC40 no problem. One quick docking to a F9US launched by Falcon Heavy from LC-39A later, and you've got 6700m/s including the kick stage. If Falcon Heavy has to scrub, no biggy. EC and STAR don't have a time limit. Together they're good for a C3 of 88.5, which is SLS Block1B beating. If you ASDS the falcon 9 with a new enlarged STAR(180?) massing 10t (16t total) then the combined FUS + STAR180 hits a C3 of 106. SLS Block2 can only manage 6t to 94 C3. (And it keeps Thiokol in business! Everybody's happy!) Edit: Some maths suggests it would be a STAR 74 to 80 or so, depending on oblateness. Easily within Falcon 9's 181" fairing envelope.
  3. I really don't understand why distributed launch isn't a bigger thing already. It's such an obviously superior mission mode for just about all unmanned purposes.
  4. I expect the first task for the high bay will be stacking a fairing on top of SN6 for high altitude testing.
  5. And here I was thinking you'd beaten me to the high bay starting construction!
  6. Something I haven't seen mentioned yet that was discussed in this article: https://www.teslarati.com/spacex-starship-sn5-raptor-test-schedule/amp/?__twitter_impression=true SN5's proof test fill was conducted exceptionally quickly. It's an extremely quick propellant load through a quick disconnect port. Also some beauty shots of GPS-III landing:
  7. Those figures are quite a bit larger than the awards as reported, each by approx a factor of 20. I shan't pretend to be able to follow the info on beta.SAM.gov, but the reported amounts are: SpaceX: $135m Dynetics: $253m National Team: $579m https://spacenews.com/nasa-selects-three-companies-for-human-landing-system-awards/
  8. I avidly follow UK politics as well as space news, so this is right up my street. It's hard to comment because of the forum rules. Suffice it to say that the current UK government need not have exited the Galileo program, but did so for ideological reasons. It then spent millions on attempting to start up its own navigation system, which was doomed to failure from the beginning (what satellites launched on what rocket from what launch site operating on what frequency?). Apparently someone then convinced them to buy a half billion £ stake in OneWeb as a solution to the "what satellite" part of the problem, despite the fact OneWeb doesn't actually have the required technology and the satellites can't be retrofitted even if they did. Follow that up with the fact that a major govt donor has a large stake in OneWeb, and this deal stinks of corruption. This is entirely on brand for this govt.
  9. It's #27. That's a fair step up from 18,19,20!
  10. Apparently cryo-testing was good enough to move on to hot fires! I wonder which raptor SN gets installed.
  11. SN5 had always looked a little denty around hatches. I'm not sure which new dent you mean? This time lapse of last night's cryo testing is awesome:
  12. This is unusual because ULA's Unique Selling Point is Always Launch On Time.